I was hoping for a difficult moral dilemma, but "do unto others" pretty much solves this one.
You could start the conversation with, "You have something you don't know is valuable, and I'd LIKE a finders fee for the discovery if you decide to sell it." I say LIKE, because he doesn't really owe you anything. The card is his whether he thinks it's worth 20c or $1000 0000. You could buy it cheaply and then sell it, of course. But that would be deception, and fail the "do unto others" test. Yes, you could give back some of the profit to him, with varying degrees of generosity, but then you're taking over the decision of who gets how much. It should be his to make.
In short, tell him. Think of anything you get as a bonus, but be prepared to gain nothing(financially - it's always funky to be funky
).
PS.Offer to sell it for him if you know the right channels. You might be able to negotiate a (bigger?)cut.
You could start the conversation with, "You have something you don't know is valuable, and I'd LIKE a finders fee for the discovery if you decide to sell it." I say LIKE, because he doesn't really owe you anything. The card is his whether he thinks it's worth 20c or $1000 0000. You could buy it cheaply and then sell it, of course. But that would be deception, and fail the "do unto others" test. Yes, you could give back some of the profit to him, with varying degrees of generosity, but then you're taking over the decision of who gets how much. It should be his to make.
In short, tell him. Think of anything you get as a bonus, but be prepared to gain nothing(financially - it's always funky to be funky
PS.Offer to sell it for him if you know the right channels. You might be able to negotiate a (bigger?)cut.